This invention relates to a hydrophilic organopolysiloxane composition for use as dental impression material which cures into a hydrophilic elastomeric or gel-like product (cured silicone rubber or cured silicone gel).
At the present, organopolysiloxane compositions are commonly used in main applications including building, electric/electronic, and dental fields. This material, however, has several problems due to the nature of siloxane that it is water repellent in itself. For example, in the building field, the surface of the material is not receptive to aqueous paints. When used as an impression material in the dental field, the material is difficult to produce precise impressions.
Approaches to these problems include the use of hydrophilic fillers such as calcium carbonate in the building field and the addition of polyether in the dental field (JP-A 2003-81732). Such approaches are insufficient in these fields since the base is dimethylpolysiloxane. The addition of only the filler leads to variant coating of aqueous paint. The internal addition of polyether allows for impression variations because the polyether can separate out of the composition or cured product thereof with the lapse of time.
JP-B 6-37558 discloses a curable composition comprising an allyl-terminated polyether as a base and a polyether-modified organohydrogenpolysiloxane as a crosslinking agent. This composition has the problems that the crosslinking agent is difficult to synthesize and the composition loses a curing ability with the lapse of time because of internal rearrangement of allyl groups at the ends of the base under the oxidizing action of a platinum catalyst.